| Issue |
136698
|
| Summary |
Bug in `SmallPtrSetImplBase::insert_imp_big`
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
headshog
|
Hi! I have found bug in `llvm::SmallPtrSetImpl::insert`. I have a function:
```c++
void removeParallelEdges(llvm::CallGraph &CG) {
for (auto &&CGNode : *CG) {
CallGraphNode *Node = CGNode.second.get();
bool FoundParallelEdge = true;
while (FoundParallelEdge) {
SmallSet<Function *, 16> Visited;
FoundParallelEdge = false;
for (auto CI = Node->begin(), CE = Node->end(); CI != CE; CI++) {
llvm::errs() << "HERE " << CI->second->getFunction() << " " << Visited.size() << "\n";
if (!Visited.insert(CI->second->getFunction()).second) {
FoundParallelEdge = true;
Node->removeCallEdge(CI);
break;
}
}
}
}
}
```
Here segmentation fault occurs with the following stacktrace:
```
#0 0x00007ffff05dd33a in llvm::SmallPtrSetImplBase::insert_imp_big(void const*) () from /lib/x86_64-linux-gnu/libLLVM.so.21.0
#1 0x000055555586baa1 in llvm::SmallPtrSetImplBase::insert_imp (this=0x7fffe6ff3408, Ptr=0x7fffa001d2a8) at /usr/lib/llvm-18/include/llvm/ADT/SmallPtrSet.h:155
#2 llvm::SmallPtrSetImpl<llvm::Function*>::insert (this=0x7fffe6ff3408, Ptr=0x7fffa001d2a8) at /usr/lib/llvm-18/include/llvm/ADT/SmallPtrSet.h:367
#3 DbgCallGraphDOTInfo::removeParallelEdges (this=this@entry=0x7fffe6ff37a8, ...)
...
```
And with output:
```
HERE 0x7f06780913a8 0
HERE 0x7f06780914e8 1
HERE 0x7f06781d6d38 2
HERE 0x7f06781d6ed8 3
HERE 0x7f06781d6fa8 4
HERE 0x7f06781d7118 5
HERE 0x7f06781d7258 6
HERE 0x7f06781d73d8 7
HERE 0x7f06781d7558 8
HERE 0x7f06781d7768 9
HERE 0x7f06781d78e8 10
HERE 0x7f06781d7a58 11
HERE 0x7f06781d7bc8 12
HERE 0x7f06781d7d58 13
HERE 0x7f06781d7ec8 14
HERE 0x7f06781d8038 15
HERE 0x7f06781d81a8 16
[1] 666112 segmentation fault (core dumped)
```
I've also tried to change LLVM version to 18 and didn't get this problem, so this bug appeared in newer version.
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